Mechanical pencil



R G. C. BOA.

MECHANICAL PENCIL.

APPLICATION FILED IAN. I7, 19H;-

' wish to the casing 10. The a support for a cap 15, frictionallymounted ROBERT GEORGE COMPANY, OF

CROMBIE BOA, OF CHICAGO, ILLINOIS, ASSIGNOB TO THE WAHL WILMINGTON,DELAWARE, A CORPORATION OF DELAWARE.

MECHANICAL PENCIL.

' Specification of Letters Patent.

Patented June 22, 1920.

* Application filed January 17, 1918. Serial No. 212,351.

To all whom it may concern.

Be it known that I, Ronna'r Gnonon CROM- nu: Boa, a subject of the Kingof England, residing at Chicago, in the county of (look and State ofIllinois, United States of America, have invented certain new and usefulImprovements in Mechanical Pencils, of which the following is aspecification.

My invention is in a mechanical pencil and has for its object theproviding of an improved support for a rubber eraser customarily presentin such pencils.

In its preferred form I have shown my invention as applied to themechanical pencil disclosed in the patent to Keeran, No. 1,130,741,issued March 9, 1915, but I do not limit myself toits use in connectionwith the pencil described in said patent.

- My invention will be best understood by reference to the accompanyingfigures, of

whichp Figure 1 is aview of an assembled pencil with the upper partshown in section;

Fig. 2 is an enlarged section of some shown in Fig. 1, and v Fig. 3 is adetail.

The pencil shown in Keeran consists of a casing 10, provided with a lead11, propelled by a suitable means through a tip 12. The rear end of thepencil parts is provided with a rubber eraser 13, which is held in asleeve 14, screwed on the rear end of the double magazine 15, saidmagazine being slidably mounted in sleeve 14 also serves as thereon,said cap serving to protect the eraser when not in use.

In my herein described invention I have constructed the sleeve 14 asshown in enlarged section in Fig. '2, said sleeve comprising two screwthreads, one, 16, being of large diameter and being 1 screwed on thedouble magazine 1:). The upper end of the sleeve 14 contains a screwthread 17 of somewhat smaller diameter and is spun in at its upper end18 (Fig. 2) to a diameter somewhat smaller than that of the eraser 13. Adisli 19, having a slot 20 therein, is screwed in the thread 17 andserves as a support for the rear end of the eraser 13.

Y 1 As said eraser is used, the sleeve 14 is unthe cited patent toscrewed from the double magazine 15, a screw driver, pen knife or othernarrow implement is inserted in the slot 20 and the disk 19 is screwedup in the thread 17 thereby forcing the eraser 13 through theconstricted portion 18 and presenting a new surface for use. Thisprocess may be continued until all of the eraser 13 has been used, whenthe disk 19 may be taken out of the sleeve 14 and a new eraser 13inserted and used as before. It will be observed that the difference indiameter between the large threads 16 and the small diameter 17 afford ashoulder against which the sleeve 14 is screwed on the double magazine15, and also that the presence of the disk 19 affords a firm surface toresist the pressure of the eraser 13 when the same is in use.

Many variations may be made from the precise structure herein shownwithout departing from the spirit of my invention.

I claim 1.In an eraser support for a pencil, the combination of a sleevehaving a large portion adapted to be fastened on the pencil and asmaller portion adapted to support an eraser, a disk supported in saidsmaller portion by a screw thread and means whereby .said disk may beadvanced.

2. In a mechanical pencil, the combination' of a pencil casing, a sleevemounted on said casing, said sleeve having an enlarged screw portionadapted to engage said cassupport an eraser, and a disk provided withscrew threads and adapted to be advanced in said smaller portion tothereby afford a firm support for the eraser.

In an eraser support for a pencil, thecombination of a sleeve having alarge por tion adapted to be fastened on the pencil,

a small portion adapted to support an eraser, a disk supported by ascrew thread in said small portion and adapted to-contact with one endof said eraser, an a slot in said disk, whereby the same may be screwedin said smaller portion to thereby gradually advance the eraser as thesame may be used. p

In witness whereof I have hereunto subscribed my name.

ROBERT GEORGE CROMBIE BOA,

and a smaller screw portion adapted to

